Answer:
$4,500
Explanation:
First we have to calculate the provisional income which shall be calculated as follow:
AGI amount: Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â $27,000
Tax exempt interest                        $200
50% of your social security benefit            $4,500
(0.50*9,000)
Total provisional income                    $31,700
Since the amount of provisional income is greater than the base amount of  $25,000 for Head of house hold but less than $34,000, therefore the Caroline will have to pay taxes on 50% of the social security benefits and hence the amount of taxable social security benefit shall be $4,500